diskimage-builder/diskimage_builder/elements/dib-python/README.rst
Paul Belanger 3e17ee3f48 Clean up dib-python symlink
We only need dib-python when we build the image, no need to leak it to
the final product.  Remove it in cleanup.d outside the chroot so
nothing can be using it.

Change-Id: I1e229caad7968fb3ab8e44ecdda427e174088d2d
Signed-off-by: Paul Belanger <pabelanger@redhat.com>
2017-04-12 14:33:57 +10:00

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==========
dib-python
==========
Adds a symlink to ``/usr/local/bin/dib-python`` which points at either a
``python2`` or ``python3`` executable as appropriate.
In-chroot scripts should use this as their interpreter
(``#!/usr/local/bin/dib-python``) to make scripts that are compatible
with both ``python2`` and ``python3``. We can not assume
``/usr/bin/python`` exists, as some platforms have started shipping with
only Python 3.
``DIB_PYTHON`` will be exported as the python interpreter. You should
use this instead of ``python script.py`` (e.g. ``${DIB_PYTHON}
script.py``). Note you can also call ``/usr/local/bin/dib-python
script.py`` but in some circumstances, such as creating a ``virtualenv``,
it can create somewhat confusing references to ``dib-python`` that
remain in the built image.
This does not install a python if one does not exist, and instead fails.
This also exports a variable ``DIB_PYTHON_VERSION`` which will either be
'2' or '3' depending on the python version which dib-python points to.
.. note::
The ``dib-python`` interpreter will be removed in ``cleanup.d``. It
is only intended for build scripts.